diff options
| author | Skyler Saleh <skylersaleh@gmail.com> | 2021-02-03 07:11:30 -0800 |
|---|---|---|
| committer | Skyler Saleh <skylersaleh@gmail.com> | 2021-05-22 15:25:18 -0700 |
| commit | 4ff429266a75d8cfdb71fd37d818baa9a75264a3 (patch) | |
| tree | c1369fe130d55cd9633435bf18c5cf95f8bc638b /Source/Core/Common/MemoryUtil.cpp | |
| parent | 8cb86e7ae01211efb540999f4fbe44c4f42e001a (diff) | |
Apple M1: MacOS 11.2 mprotect restrictions
In MacOS 11.2 mprotect can no longer change the access protection settings of
pages that were previously marked as executable to anything but PROT_NONE. This
commit works around this new restriction by bypassing the mprotect based write
protection and instead relying on the write protection provided by MAP_JIT.
Diffstat (limited to 'Source/Core/Common/MemoryUtil.cpp')
| -rw-r--r-- | Source/Core/Common/MemoryUtil.cpp | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/Source/Core/Common/MemoryUtil.cpp b/Source/Core/Common/MemoryUtil.cpp index e81637912e..7aec9df40f 100644 --- a/Source/Core/Common/MemoryUtil.cpp +++ b/Source/Core/Common/MemoryUtil.cpp @@ -41,7 +41,9 @@ void* AllocateExecutableMemory(size_t size) #else int map_flags = MAP_ANON | MAP_PRIVATE; #if defined(_M_ARM_64) && defined(__APPLE__) - // This check is in place to prepare for x86_64 MAP_JIT support. + // This check is in place to prepare for x86_64 MAP_JIT support. While MAP_JIT did exist + // prior to 10.14, it had restrictions on the number of JIT allocations that were removed + // in 10.14. if (__builtin_available(macOS 10.14, *)) map_flags |= MAP_JIT; #endif @@ -206,7 +208,10 @@ void WriteProtectMemory(void* ptr, size_t size, bool allowExecute) DWORD oldValue; if (!VirtualProtect(ptr, size, allowExecute ? PAGE_EXECUTE_READ : PAGE_READONLY, &oldValue)) PanicAlertFmt("WriteProtectMemory failed!\nVirtualProtect: {}", GetLastErrorString()); -#else +#elif !(defined(_M_ARM_64) && defined(__APPLE__)) + // MacOS 11.2 on ARM does not allow for changing the access permissions of pages + // that were marked executable, instead it uses the protections offered by MAP_JIT + // for write protection. if (mprotect(ptr, size, allowExecute ? (PROT_READ | PROT_EXEC) : PROT_READ) != 0) PanicAlertFmt("WriteProtectMemory failed!\nmprotect: {}", LastStrerrorString()); #endif @@ -218,7 +223,10 @@ void UnWriteProtectMemory(void* ptr, size_t size, bool allowExecute) DWORD oldValue; if (!VirtualProtect(ptr, size, allowExecute ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE, &oldValue)) PanicAlertFmt("UnWriteProtectMemory failed!\nVirtualProtect: {}", GetLastErrorString()); -#else +#elif !(defined(_M_ARM_64) && defined(__APPLE__)) + // MacOS 11.2 on ARM does not allow for changing the access permissions of pages + // that were marked executable, instead it uses the protections offered by MAP_JIT + // for write protection. if (mprotect(ptr, size, allowExecute ? (PROT_READ | PROT_WRITE | PROT_EXEC) : PROT_WRITE | PROT_READ) != 0) { |